With continuous development of network technologies, transmitting all types of data by using network technologies has become an indispensable part of people's life and work.
With continuous development of a VoIP (Voice over Internet Protocol, for digitizing analog voice signals) technology, RTP (Real-time Transport Protocol) is widely applied in the transmission of media data over a broadband network. Meanwhile, security problems of a data channel during the data transmission gradually attract attention of people. However, there are some security loopholes in the conventional VoIP networking, and enterprises have a possibility of leaking confidential information.
During the data transmission between terminal A and terminal B, signaling negotiation processes initiated by terminal A and terminal B are standard processes. In these standard processes, formats and content of each piece of signaling transmitted between the terminals and a Session Initiation Protocol (SIP) server are all known by those skilled in the art. Therefore, the foregoing signaling negotiation processes, including registration negotiation, call negotiation, and the like, are easily constructed by using conventional software technologies, for example, signaling negotiation can also be implemented successfully under the SIP server by using illegal software, so that an illegal data channel is established to transmit illegal data through the SIP server.